OP0210-HPR THE OCCURRENCE OF OVERWHELMING FATIGUE IN INDIVIDUALS WITH KNEE OSTEOARTHRITIS: A DAILY DIARY STUDY
Authors: M. W. J. Heijman, C. van den Ende, C. Popa, J. E. Vriezekolk
Journal: Annals of the Rheumatic Diseases (2022)

Background Cross sectional research shows that nearly half of the individuals with osteoarthritis (OA) experience fatigue and over one third experience severe fatigue (1). However, few studies have addressed the unpredictable and fluctuating course of fatigue in OA including the occurrence of overwhelming fatigue as evidenced from qualitative research (2). In-depth understanding of the course of fatigue and its determinants may inform clinical decision making and treatment. Objectives To explore 1) the occurrence of overwhelming fatigue and its determinants and 2) the variability of daily experienced fatigue in individuals with knee OA. Methods A daily diary design. 73 participants with a self-reported diagnosis of knee OA aged &gt;40 years and in possession of a Smartphone completed a baseline questionnaire on demographics, health status (EQ5D-VAS), and self-efficacy (Arthritis Self-Efficacy Scale (ASES)). This was followed by daily assessments with regard to overwhelming fatigue, fatigue severity, pain, sleep, and perceived exertion of physical activities (PEPA) over a 7 day period. A yes/no format was used to assess overwhelming fatigue and a numeric rating scale (NRS, 0-10) was used to assess fatigue severity, pain, sleep, and PEPA. The variability of fatigue was assessed by calculating the standard deviation (SD) per participant over this 7 day period. Comparisons between participants with and without overwhelming fatigue were conducted by unpaired t-tests and Pearson’s chi-square tests where appropriate. Results 47 participants were included in the analysis. Overwhelming fatigue occurred at least once in 26 (55%) participants with mean= 2.7 (SD= 1.4) over a 7 day period. Differences of participants with and without overwhelming fatigue are displayed in Table 1. Table 1. Characteristics of participants (n=47) included in the analysis. Characteristics* All participants (n=47 ) Participants with overwhelming fatigue (n=26 ) Participants without overwhelming fatigue (n=21 ) Difference (95% CI ) p-value Age 63.4 (8.6) 61.7 (8.5) 65.5 (8.5) -3.8 (-8.8; 1.2) 0.13 Female (n (%)) 39 (83%) 23 (88%) 16 (76%) 0.47 BMI 27.4 (4.6) 28.0 (5.1) 26.5 (3.8) 1.5 (-1.1; 4.1) 0.25 Health status 67.5 (13.8) 66.0 (13.5) 69.5 (14.2) -3.5 (-11.7; 4.7) 0.39 ASES pain 2.9 (1.0) 3.2 (0.8) 2.5 (1.1) 0.7 (0.1; 1.3) 0.02 ASES os 2.5 (0.8) 2.7 (0.8) 2.2 (0.7) 0.5 (0.1; 1.0) 0.02 Fatigue severity 4.9 (1.7) 5.5 (1.5) 4.1 (1.6) 1.3 (0.4; 2.3) 0.01 Pain 4.2 (1.9) 4.8 (1.6) 3.4 (2.0) 1.4 (0.3; 2.5) 0.01 Sleep 5.9 (1.6) 5.5 (1.7) 6.4 (1.4) -0.9 (-1.8; -0.0) 0.05 PEPA 4.9 (1.2) 5.0 (1.2) 4.8 (1.3) 0.2 (-0.6; 0.9) 0.64 ASES, Arthritis Self-Efficacy Scale; ASES os, other symptoms; PEPA, perceived exertion of physical activities. For health status, ASES pain, ASES os, and sleep, higher scores reflect better outcomes; for PEPA, higher scores reflect more PEPA; for fatigue severity and pain, higher scores reflect higher levels. *mean (SD) unless otherwise statedg. The variability of daily experienced fatigue per participant ranged from SD= 0.2 to 2.9 (Figure 1). This was not significantly different between participants with and without overwhelming fatigue. Figure 1. Standard deviations of average fatigue severity over a 7 day period per participant (n=47). Conclusion Our findings suggest that more than half of the participants experienced at least one episode of overwhelming fatigue and that this is related to self-efficacy, fatigue severity, pain, and sleep. Fatigue remained fairly stable over time by the majority of participants. References [1]Overman CL, Kool MB, da Silva JAP, Geenen R. The prevalence of severe fatigue in rheumatic diseases: an international study. Clin Rheumatol. 2016;35:409–15. [2]Power JD, Badley EM, French MR, Wall AJ, Hawker GA. Fatigue in osteoarthritis: A qualitative study. BMC Musculoskeletal Disorders. 2008;9:63. Acknowledgements We would like to thank Yvonne Peters for her involvement in the study design and data collection. Disclosure of Interests None declared